The singer and actress, 20, met the heartthrob actor, 49, for the first time at Sunday's MTV Movie Awards. And she was so starstruck that she barely held it together.

"I was in my dressing room, and I had just finished performing," Gomez says in an interview airing Tuesday on The Ellen DeGeneres Show. "And they knocked on my door, and they said Brad Pitt would like to come in. And I was like, well, he can come in!"

Pitt wanted a photo of the two of them together, as his kids are apparently fans. Meanwhile, Gomez was just focused on trying not to completely freak out.

"I was trying to play cool and be really nice," she says. "And as soon as he walked out, I ran and I hid under the craft-service table for like two minutes because I couldn't believe it was happening."

DeGeneres also delicately inquires about Gomez's love life in the wake of her split with Justin Bieber. "I mean, Brad Pitt is not available," she joked. "But there must be somebody."